The present invention relates to external sealing of pipe joints.
More particularly, the invention provides a wide seal strip useful in combination with a coupling for pipes, the length, and hence the diameter of the seal strip being adjustable also on site.
Wide flexible seals having a sealing member proximate to each edge are known, and have been marketed by the present inventor and others for some years. The seal has two active lips, a first of which contacts a first pipe and the second lip contacts the second pipe. The seal is typically held inside a pipe coupling. The substantially-flat connecting portion of the seal prevents leakage from the space(s) between the pipes and between the active seal lips.
Such seals are made as a ring and fit into the respective coupling. Accordingly for each coupling a special seal is required, meaning that a large number of seals for each diameter is to be manufactured.
According to the invention a seal strip is provided to be cut to the required diameter.
When the precise outside diameter of the pipes to be connected and sealed is known, the seal strip can be accurately cut to length beforehand in a manner allowing the ends of the seal strip to match each other closely and thus prevent leakage there between. In the factory or at the supplier's workplace it is easy to execute the accurate cut required. However when the seal is cut to the required length on site by hand using scissors or a sharp knife, the two ends of the seal will not match well, leading to possible leakage there between. Furthermore, there is also a danger of personal injury when such cutting is carried out on site.
A search of US Patents produced no relevant disclosures relating to this problem.